Various devices for detecting the position of passive objects are known, such as the devices disclosed in U.S. Pat. Nos. 4,144,449 and 4,247,767. These devices, however, are limited to detecting position and cannot detect multiple finger gestures. Moreover, they are fairly complicated and require frames and encompassing light sources as well as several sensors, the latter being fairly expensive. U.S. Pat. No. 4,746,770 discloses a method and device for isolating and manipulating graphic objects on a computer video monitor. This device which also uses a frame and several sensors is not easily adapted to playing and generating music, although it can detect multiple fingers.
Detecting position and using it to control music is described in Max Mathew's "The Sequential Drum" in Computer Music Journal, Vol. 4, No. 4 (Winter 1980). The device described in this article, however, only detects the movement of one finger and also requires the use of several sensors.
It would be desirable, therefore, to have a gesture sensing device which was particularly adept at sensing and tracking the movement of multiple fingers and which could use these gestures to generate or control sound, light and/or the motion of physical objects. Preferably, this device could simultaneously extract several parameters from the movement of multiple fingers and use these parameters to control the creation of sound and/or light. It would also be desirable to have a gesture sensing device which would be easily playable as a musical instrument and which did not require an elaborate frame and several sensors.